Iowa is a state located in the Midwestern United States, an area often referred to as the "American Heartland." It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of the French colony of New France. After the Louisiana Purchase, settlers laid the foundation for an agriculture-based economy in the heart of the Corn Belt. Iowa is often known as the "Food Capital of the World", but Iowa's economy, culture, and landscape are diverse. In the mid and late 20th century, Iowa's agricultural economy transitioned to a diversified economy of advanced manufacturing, processing, financial services, biotechnology, and green energy production. Iowa has been listed as one of the safest states in which to live. Des Moines is Iowa's capital and largest city.
Iowa is bordered by the Mississippi River on the east; the Missouri River and the Big Sioux River on the west; the northern boundary is a line along 43 degrees, 30 minutes north latitude.[9][note 1] The southern border is the Des Moines River and a line along approximately 40 degrees 35 minutes north, as decided by the U.S. Supreme Court in Missouri v. Iowa after a standoff between Missouri and Iowa known as the Honey War. Iowa has 99 counties, but 100 county seats because Lee County has two. The state capital, Des Moines, is located in Polk County.
Iowa's bedrock geology generally increases in age from west to east. In northwest Iowa Cretaceous bedrock is ca. 74 million years old, in eastern Iowa Cambrian bedrock dates to ca. 500 million years ago.
Despite popular perception, Iowa is generally not flat; most of the state consists of rolling hills. Prior divides Iowa into eight landforms based on glaciation, soils, topography, and river drainage. Loess hills lie along the western border of the state, some of which are several hundred feet thick. In the northeast, along the Mississippi River, is a section of the Driftless Zone, which in Iowa consists of steep hills and valleys which appear almost mountainous.
There are several natural lakes in the state, most notably Spirit Lake, West Okoboji Lake, and East Okoboji Lake in northwest Iowa (see Iowa Great Lakes). To the east lies Clear Lake. Man-made lakes include Lake Odessa, Saylorville Lake, Lake Red Rock, Coralville Lake, Lake MacBride, and Rathbun Lake. The northwest part of the state also contains a considerable number of remnants of the once common wetland areas such as Barringer Slough.